Feeders used in the care of laboratory animals are well known. Such feeders are typically configured in a hopper-like arrangement and attached to the side of an animal's cage. They typically have an upper opening for the addition of feed and a lower opening from which the laboratory animal can receive feed as desired. Thus, feed is placed in the feeder through the opening formed in the top thereof and is gravity fed to the lower opening, typically into a tray from which the animal feeds.
In laboratory testing environments, it is important to be sure that the food eaten by the laboratory animal does not become contaminated by urine, feces, or any other undesirable material. Such contaminants, when introduced into the food of a laboratory animal, may adversely affect or even invalidate the results of experiments in which substances are tested by mixing them with the laboratory animal's food. The validity of such experiments typically depends upon the purity and known content of the food provided to the laboratory animal.
Additionally, even when such test substances are not added to the food, contaminants may tend to adversely affect the life span and physical condition of the laboratory animal. This, in turn, becomes a particular problem when, as is the usual case, it is important to test laboratory animals which are in normal physical condition.
In large laboratory settings, where multiple cages are commonly stacked one on top of another, there is the possibility for urine, feces, dust, and other airborne contaminate to fall into the feeders of the lower cages and thereby contaminate the food. As such, it is desirable to provide a means for limiting the likelihood of the laboratory animal's food becoming contaminated.
Additionally, it is frequently desirable to know the amount of food consumed by a laboratory animal. Such is generally the case when the food contains a substance being tested. Thus, in order to know the amount of the substance being tested which is eaten by the laboratory animal, it is necessary to know how much of the laboratory animal's food has been consumed thereby. Spillage must be measured and accounted for such that it is not assumed to have been eaten by the laboratory animal. Thus, it is desirable to limit spillage and thereby reduce the amount of the food which must be measured in order to increase the accuracy and effectiveness of the test procedure.
Additionally, when granular or powder-like substances are fed to laboratory animals, such substances tend to cake up or compact due to the feeding action of the animal and the presence of moisture. Moisture, i.e. saliva, is typically contributed by the animal as it feeds, thus causing the feed to compact out of the reach of the animal's mouth. Such compaction generally results in the formation of a cone-shaped void about the animal's snout such that the remaining food is just out of reach.
As such, it is desirable to provide a laboratory animal feeder which mitigates the potential for contamination, limits spillage, and is not subject to compaction of the feed contained therein.